Coral Bark Maple Sango Kaku: how increase red bark?

wynswrld98(z7 WA)October 16, 2007

Both my parents (in CA) and myself own Sango Kaku Coral Bark Maples, each about 6' tall, started out with beautiful "coral" bark but it has turned more brown/green over time, am curious if there are any nutrients or tricks to try and increase the redness of the bark. Thanks in advance!

There is nothing you can do,the red/coral bark exists only on younger stems.As it gets older,the coral color will eventually disappear and that is normal part for this particular cultivar.This is base on my experience,if someone have a better way to improve it,I would love to hear it.

We've each had these trees about 6 months and the trunk bark was even reddish when we bought the trees but now it's brownish/green so that wasn't new growth at all when we bought it. Both trees are planted in full sun.

The trunk bark color does fade with time - that's pretty much a given and the nature of the tree. There's nothing you can do for that. But the branch and stem color should be pretty intense, especially in winter as giboosi mentions. My own tree, going on 15 years old and without any serious pruning to date, puts on a spectacular show each winter with stem color.

You should also realize that this is one of the most popular cultivars of Japanese maples and it is propagated very heavily. The gene pool is not precise and some of these zillions of clones may be less genetically true to form than others and may not color up as well as a true clone.

Yes, Colvos Creek nursery raised seedlings recently and found many of them to resemble the parent, so there may have been many different clones all put on the market over the years by various growers as the same cultivar. These days you can also purchase other cultivars that have better stem color retention. The 'Sango Kaku' is pretty quick to go gray inside and below, only the youngest wood being coral; older, twiggy specimens may not have very much impact from any distance - the red younger twigs much smaller and thinner than when the tree was recently planted. Those with small gardens may wish to grow theirs as a regularly pruned specimen that is kept producing young, vigorous shoots.

There is no specific nutrient for increasing the color. But a good flush of a seasons growth yeilds the best color (and the previous seasons growth once in a good fertilizer pattern). The younger the growth, the better the color...but two to three years old can/will also show nice color.
BUT....depending on where you are in WA, pushing this same growth can set you up for the "black death" of japanese maples (psuedomonas). If you roll the dice and play, do not fertilize after the end of July and restrict water after the end of August (rule of thumb on water, depends on where you are at).

Pretty difficult to answer :-) In general, most newly planted trees and shrubs require NO fertilizer and ongoing needs will depend on your existing soil conditions. If you have doubts about your soil's fertility, have it tested. FWIW, I fertilize only those maples I grow in containers - inground maples get mulched, period.

Also impossible to say how often or how much to water - that depends on climate, siting of the tree, and soil conditions. Japanese maples are not very drought tolerant so even established trees may need periodic deep watering. Newly planted trees should be kept moist - not wet - throughout summer or until fall rains commence. Best to test the soil physically by finger down next to the root ball - it should be just moist to the touch.

Some of the photo's of coral bark maple are misleading.
A whole row of bush stews 36-48 inches tall, blood red against the snow.
They do this with Bloodtwig Dodwood, too.
The photo's are to get sales, many vargated new growth looses its color as it manture.

Hey Dallas, I had to read your post twice! I must admit your the first ive ever heard of painting a 'Sango Kaku' trunk red. Ive never heard that one before, but i have seen dormant trees spray painted white before christmas time and strung with lights.Not sure of what type of trees...Im always doing 65. They are leafing out now and look happy and the white is fading.
Happy touch -up!

My Sango kaku never seemed to get very red until I moved it from a protected location to an open area of my garden. It has always been in a container and grows just fine. Late this past Winter, the stems turned bright red and I was quite pleased. However, just like many red-leaf maples, the red soon faded as the season wore-on. Now the stems are yellow-orange, but the foliage is quite stunning. I think that the tree needs open access to cold winter breezes in order for the red stems to show...